[Clinical evaluation of four tumor markers (CEA, TPA, CA50 and CA72-4) in colorectal cancer].

In a total of 194 cases, consisting of 86 cases of colorectal cancer undergone operation later, 7 cases of non resectable cancer, 34 cases of recurrence, 43 cases of NED (no evidence of a recurrence after radical surgery for colorectal cancer) and 24 cases of benign colorectal disease, serum CEA, TPA, CA50 and CA72-4 levels were determined. The positivity rate was high for all four markers in stage V cases among 86 cases of colorectal cancer, and in cases of non resectable cancer and cases of recurrence. The highest positive rate was obtained with CEA. On the contrary, in cases of stage I to IV the positivity rates of these four tumor markers were as low as 0 to 34.8%. Out of 127 cases of colorectal cancer excluded of 43 NED cases, 52 cases were negative for all four tumor markers and 14 cases were positive only for CEA. In 49 cases, CEA and at least one of the other three tumor markers gave positive results. In 12 cases, CEA gave negative results and at least one of the other three tumor markers positive results. In conclusion, measurement of blood levels of these tumor markers is limited of its usefulness in early diagnosis of colorectal cancer. However, in the diagnosis of advanced stage and of recurrence during the postoperative follow-up period the measurement of tumor markers provides useful information. CEA is most sensitive among the four tumor markers tested and any combination of these four markers is not advantageous because of an increase in false positivity rate.